In television broadcast, available frequency bands of carrier waves and available channel numbers are determined according to public rules, independently of kinds of analog and digital. These are referred to as “physical channels”. In Japan, VHF (Very-High Frequency) and UHF (Ultra-High Frequency) bands are assigned to the ordinary analog broadcast, and the UHF band is assigned to the digital terrestrial broadcast. As the digital broadcast has started, program contents that are substantially the same as those provided by the conventional analog broadcast have also been provided on the digital channel. However, the assigned physical channel number of the digital broadcast is different from that of the analog broadcast so that the analog broadcast and the digital broadcast use different channel numbers for the program of the same broadcast station and the same contents, respectively. Accordingly, such a system has been employed that the digital broadcast employs a virtual channel number apart from the physical channel number, and the channel number equal to that of the corresponding analog broadcast program can also assigned to the program. Further, in the digital broadcast, a plurality of sub-channels can be assigned to one channel. Thereby, it is possible, e.g., to broadcast a baseball game on different sub-channels on which different commentators appear, respectively. Since this virtual channel number is described in a data field representing the virtual channel in data of the digital broadcast, the virtual channel number can be recognized by correctly receiving the digital broadcast data. Although a concept of the virtual channel is not employed for the analog broadcast, it may be regarded in some cases that the physical channel is the virtual channel.
In a past age of the analog broadcast, about ten channels at most are selected by depressing channel selection buttons bearing numbers “1”-“12”. However, as the digital broadcast started, the number of channels has extremely increased, and nearly up to 100 channels including sub-channels are selectable. Therefore, a manner of selecting the channels by increment/decrement buttons has been an important factor in the channel selection, in addition to direct selection of an intended channel by a combination of channel number buttons.
In the broadcast wave, the frequency band of the carrier wave that each broadcast station (business entity) can use in each region or district is determined according to the public rules as already described. Also, the reach of the wave is also restricted. Therefore, in certain districts, the programs are not provided on all the physical channels, and there are many physical channels that are not used for the broadcast. When the user successively selects the physical channels containing many useless channels in a dispersed fashion by the increment/decrement buttons, the user must perform wasteful operations. Further, the channel allocation is not performed uniformly in all the districts, and depends on the district. Therefore, many television sets are configured as follows. In an operation of installing the television set, the television set once attempts to receive programs on all the physical channels, stores information about the available channels, i.e., channels allowing the program reception in a memory (e.g., a data memory of a control microcomputer), and allows successive selection of only the available channels through the increment/decrement buttons according to the information. When the channel map in the memory is created in order of physical channels, the channel selected by the increment/decrement buttons is successively displayed in the order of the physical channels. When the channel map is stored in order of virtual addresses, the channel selected by the increment/decrement buttons is successively displayed in the order of the virtual channels.
Since the digital broadcast started, many television sets are provided with a configuration in which an electronic program guide for several channels is displayed on one screen, and right/left/up/down buttons can be operated to select a desired program in the guide for watching or unattended recording. For this, the television set extracts the program information about respective channels from the received data in order of storage in the channel map, creates the electronic program guide based on the extracted data and displays it. In the electronic program guide, program titles on the respective channels are arranged from the left to the right in the order of storage in the channel map. On the screen, an image of a television program guide on a newspaper is displayed, the times are arranged vertically and the channels are arranged laterally. The laterally arranged channels can be selected by the left/right buttons in the order of storage in the channel map. Also, the time can be selected by the up/down buttons. However, only the information about several channels is displayed on the single screen. Therefore, when the right button is further depressed after the rightmost channel is selected, the electronic program guide of other channel(s) is displayed one program at a time or one screen image at a time.